World number two Rafael Nadal was knocked out of the US Open in the fourth round by an inspired performance from fellow Spaniard David Ferrer.
Nadal played with heavy strapping on his knee throughout the match
In a tight match dominated by powerful rallies, Nadal won the first set before losing 7-6 4-6 6-7 2-6.
Nadal, apparently carrying an injury, was broken twice in the fourth set to end a three-and-a-half hour match that finished at 0145 in New York.
Ferrer, 25, will play Argentine Juan Ignacio Chela in the quarter-finals.
The number 15 seed had mixed emotions after knocking second seed Nadal out of the tournament.
"I am very tired. I had to run a lot," said Ferrer.
"I am happy for myself - it is a very special night for me but I am sorry for my friend Rafa. In the tough moments he plays very well."
Ferrer produced some blistering strokes to finish off Nadal
Nadal was full of praise for Ferrer, who he said was "having an unbelievable season".
"He's one of the best players in the world right now. He's a very tough player, very fast. For me, it's not a surprise," said Nadal.
Ferrer had lost his previous four matches against Nadal but his heavy forehand groundstrokes proved too much for the world number two, who has been hampered by a knee injury.
Ferrer hit 48 winners in all to match his previous best performance in a grand slam - reaching the quarter-finals of the 2005 French Open.